A wireless local area network (WLAN for short) is a network system in which data is transmitted over the air by using a radio frequency technology. With wide application of an intelligent terminal, people have ever-increasing demands for network data traffic, and using the WLAN to bear the traffic has become one of very important manners of transmitting information and data.
For development of a WLAN technology, a standard of the WLAN technology needs to be formulated, popularized, and applied. Institute of Electrical and Electronics Engineers (IEEE for short) 802.11 series are main standards of the WLAN, and go through several generations of mainstream standards such as 802.11, 802.11b/g/a, 802.11n, and 802.11ac.
The WLAN technology is based on a computer network and wireless communications technology, and in a computer network structure, a logical link control (LLC for short) layer and an application layer above the LLC layer may have a same or different requirements for different physical layers (PHY for short). Therefore, a WLAN standard is mainly for the physical layer and a Media Access Control (MAC for short) layer, and relates to a used technical specification and technical standard, such as a radio frequency range and an air interface communications protocol.
A physical layer frame in the WLAN standard may also be referred to as a physical layer convergence procedure (PLCP for short) protocol data unit (PPDU for short), and includes a PLCP header and a PLCP service data unit (PSDU for short). The PLCP header mainly includes a training field and a signaling (SIG for short) field.
Currently, the 802.11ax that is being researched and formulated continues evolving the WLAN technology. In the 802.11ax standard, orthogonal frequency division multiple access (OFDMA for short) is used to improve transmission efficiency. However, there is no OFDMA-based design solution for common signaling in the WLAN system at present.